Iran must prove peaceful nuclear intentions: US

Iran must commit to concrete and verifiable steps to assure about the peaceful nature of its nuclear programme before any deal can be struck with six world powers that would lead to a gradual lifting of the international sanctions on Tehran, the US has said.

The message from a senior US official came as top diplomats from P5+1 countries -- France, Britain, Germany, Russia, China and US -- began negotiations with Iran on its nuclear weapons programme for which they have set a deadline of July 20 to reach an agreement.

This is the sixth round of talks since February this year.

"Iran's negotiators have been quite serious throughout this process. There does remain a significant discrepancy, however, between Iran?s seeming intent with respect to its nuclear programme and the actual content of that programme to date," the senior US Administration official told reporters.

"Iranian officials have stated repeatedly and unambiguously that they have no intention of building a nuclear weapon, which is not a hard proposition to prove.? All we're asking is for Iran to commit to concrete and verifiable steps to show to the world what they've repeatedly said is indeed true," the official said.

"Ultimately, it is Iran's decision about whether they're willing to give the international community the kind of assurances and verification to match what they say about the peaceful nature of their nuclear program, the official said.

The P5+1 countries remain committed to the July 20 as the deadline for these talks.

"An extension is by no means automatic, as some have made it seem in the press.? All parties have to agree to one.? We believe there is still time to reach an agreement, and that is what we are focused on each and every day," the official added.

This negotiation, the official said, is about enhancing the security of the world by taking the concerns the international community has off the table, if that's possible; hopefully, opening a door for Iran to enter back into the international community.

Officials said Iran's future enrichment programme would have to be "a fraction" of its current activities under a final nuclear deal. "It has to be very limited a fraction of what they currently have ? and that is a discussion that we are willing to have," the official said.